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434 result(s) for "Yu, Yong-Qiang"
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Xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating endoplasmic reticulum stress-dependent CHOP pathway
Xanthatin is a natural sesquiterpene lactone purified from Xanthium strumarium L. , which has shown prominent antitumor activity against a variety of cancer cells. In the current study, we investigated the effect of xanthatin on the growth of glioma cells in vitro and in vivo, and elucidated the underlying mechanisms. In both rat glioma C6 and human glioma U251 cell lines, xanthatin (1–15 μM) dose-dependently inhibited cell viability without apparent effect on the cell cycle. Furthermore, xanthatin treatment dose-dependently induced glioma cell apoptosis. In nude mice bearing C6 glioma tumor xenografts, administration of xanthatin (10, 20, 40 mg·kg −1 ·d −1 , ip, for 2 weeks) dose-dependently inhibited the tumor growth, but did not affect the body weight. More importantly, xanthatin treatment markedly increased the expression levels of the endoplasmic reticulum (ER) stress-related markers in both the glioma cell lines as well as in C6 xenografts, including glucose-regulated protein 78, C/EBP-homologous protein (CHOP), activating factor 4, activating transcription factor 6, spliced X-box binding protein-1, phosphorylated protein kinase R-like endoplasmic reticulum kinase, and phosphorylated eukaryotic initiation factor 2a. Pretreatment of C6 glioma cells with the ER stress inhibitor 4-phenylbutyric acid (4-PBA, 7 mM) or knockdown of CHOP using small interfering RNA significantly attenuated xanthatin-induced cell apoptosis and increase of proapoptotic caspase-3. These results demonstrate that xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating the ER stress-related unfolded protein response pathway involving CHOP induction. Xanthatin may serve as a promising agent in the treatment of human glioma.
The DIRECT consortium and the REST-meta-MDD project: towards neuroimaging biomarkers of major depressive disorder
Despite a growing neuroimaging literature on the pathophysiology of major depressive disorder (MDD), reproducible findings are lacking, probably reflecting mostly small sample sizes and heterogeneity in analytic approaches. To address these issues, the Depression Imaging REsearch ConsorTium (DIRECT) was launched. The REST-meta-MDD project, pooling 2428 functional brain images processed with a standardized pipeline across all participating sites, has been the first effort from DIRECT. In this review, we present an overview of the motivations, rationale, and principal findings of the studies so far from the REST-meta-MDD project. Findings from the first round of analyses of the pooled repository have included alterations in functional connectivity within the default mode network, in whole-brain topological properties, in dynamic features, and in functional lateralization. These well-powered exploratory observations have also provided the basis for future longitudinal hypothesis-driven research. Following these fruitful explorations, DIRECT has proceeded to its second stage of data sharing that seeks to examine ethnicity in brain alterations in MDD by extending the exclusive Chinese original sample to other ethnic groups through international collaborations. A state-of-the-art, surface-based preprocessing pipeline has also been introduced to improve sensitivity. Functional images from patients with bipolar disorder and schizophrenia will be included to identify shared and unique abnormalities across diagnosis boundaries. In addition, large-scale longitudinal studies targeting brain network alterations following antidepressant treatment, aggregation of diffusion tensor images, and the development of functional magnetic resonance imaging-guided neuromodulation approaches are underway. Through these endeavours, we hope to accelerate the translation of functional neuroimaging findings to clinical use, such as evaluating longitudinal effects of antidepressant medications and developing individualized neuromodulation targets, while building an open repository for the scientific community.
Correlation between Non-Alcoholic Fatty Liver Disease and Visceral Adipose Tissue in Non-Obese Chinese Adults: A CT Evaluation
To investigate the correlation between non-alcoholic fatty liver disease and visceral adipose tissue in non-obese Chinese adults using computed tomography (CT). The study included 454 subjects undergoing abdominal CT scan. Degree of CT attenuation in liver and spleen, and the degree of fat infiltration in liver were evaluated according to three indices: the attenuation value of liver parenchyma (CT ), the attenuation ratio of liver and spleen (LS ) and the attenuation difference between liver and spleen (LS ). Visceral fat area (VFA) and total fat area (TFA) at L2/3 and L4/5 levels were measured, and the abdominal subcutaneous fat area (SFA) was calculated. Bivariate correlation analysis was carried out to determine the correlation among these factors. In men, VFA, SFA and TFA at L2/3 and L4/5 levels showed significant differences in terms of the three indices to distinguish fatty liver from non-fatty liver (all, < 0.001). In men, all the three indices showed negative correlation with TFA, SFA and VFA (all, < 0.001). The negative correlation between the three indices and VFA at the L2/3 level was higher than at L4/5 level ( = -0.476 vs. = -0.340 for CT , = -0.502 vs. = -0.413 for LS , = -0.543 vs. = -0.422 for LS , < 0.001, respectively). The negative correlation between LS , LS and VFA at L2/3 and L4/5 levels was higher than SFA at the corresponding level. In women, all the three indices showed negative correlation with VFA and TFA at L2/3 and L4/5 levels, and the negative correlation between CT and VFA was higher at L2/3 level than at L4/5 level ( = -0.294 vs. = -0.254, < 0.001). In non-obese Chinese adults, the degree of hepatic fatty infiltration showed a strong correlation with abdominal fat on CT. VFA at L2/3 level was more closely related to fatty liver compared with VFA at L4/5 level.
Value of Echocardiography and Cardiac Magnetic resonance in assessing left ventricular function in breast and gastric cancer patients after Anthracycline Chemotherapy
Background Echocardiography (ECHO) and cardiac magnetic resonance imaging (MRI) are used to observe changes in the left ventricular structure in patients with breast and gastric cancer after 6 cycles of chemotherapy. Based on the observed values, we aimed to evaluate the cardiotoxicity of anthracyclines in cancer patients and to analyze the consistency of the two examination methods in assessing left ventricular function after chemotherapy. Methods From January 2020 to January 2022, the data of 80 patients with malignant tumors who received anthracycline chemotherapy (breast cancer, n = 40; gastric cancer, n = 40) and 40 healthy volunteers (Control group) were retrospectively collected. Serum high-sensitivity cardiac troponin T (hs-cTnT) levels were detected by an automatic immunoassay analyzer. Left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) were measured by cardiac MRI and 2-dimensional ECHO using the biplane Simpson’s method. Results Compared with baseline values, serum high-sensitivity cardiac troponin T (hs-cTnT) levels were significantly increased in patients with breast cancer and gastric cancer after 6 cycles of chemotherapy ( P  < 0.05). In addition, LVEDV, LVESV and LVEF measured with MRI were higher than those detected by ECHO in cancer patients after 6 cycles of chemotherapy ( P  < 0.05). And the Bland-Altman plot analysis showed that LVEDV, LVESV and LVEF measured by the two examination methods were in good agreement. Conclusion Breast and gastric cancer patients exhibited elevated levels of hs-cTnT after 6 cycles of chemotherapy, indicating potential cardiotoxicity. Additionally, cardiac MRI and 2-dimensional ECHO showed good agreement in assessing left ventricular function, with ECHO tending to underestimate volume measurements compared to MRI.
Value of fractional-order calculus (FROC) model diffusion-weighted imaging combined with simultaneous multi-slice (SMS) acceleration technology for evaluating benign and malignant breast lesions
Background This study explores the diagnostic value of combining fractional-order calculus (FROC) diffusion-weighted model with simultaneous multi-slice (SMS) acceleration technology in distinguishing benign and malignant breast lesions. Methods 178 lesions (73 benign, 105 malignant) underwent magnetic resonance imaging with diffusion-weighted imaging using multiple b-values (14 b-values, highest 3000 s/mm 2 ). Independent samples t-test or Mann-Whitney U test compared image quality scores, FROC model parameters (D,, ), and ADC values between two groups. Multivariate logistic regression analysis identified independent variables and constructed nomograms. Model discrimination ability was assessed with receiver operating characteristic (ROC) curve and calibration chart. Spearman correlation analysis and Bland-Altman plot evaluated parameter correlation and consistency. Results Malignant lesions exhibited lower D, and ADC values than benign lesions ( P  < 0.05), with higher values ( P  < 0.05). In SSEPI-DWI and SMS-SSEPI-DWI sequences, the AUC and diagnostic accuracy of D value are maximal, with D value demonstrating the highest diagnostic sensitivity, while value exhibits the highest specificity. The D and combined model had the highest AUC and accuracy. D and ADC values showed high correlation between sequences, and moderate. Bland-Altman plot demonstrated unbiased parameter values. Conclusion SMS-SSEPI-DWI FROC model provides good image quality and lesion characteristic values within an acceptable time. It shows consistent diagnostic performance compared to SSEPI-DWI, particularly in D and values, and significantly reduces scanning time.
A sensitive ultraviolet light photodiode based on graphene-on-zinc oxide Schottky junction
In this study, we present a simple ultraviolet (UV) light photodiode by transferring a layer of graphene film on single-crystal ZnO substrate. The as-fabricated heterojunction exhibited typical rectifying behavior, with a Schottky barrier height of 0.623 eV. Further optoelectronic characterization revealed that the graphene-ZnO Schottky junction photodiode displayed obvious sensitivity to 365-nm light illumination with good reproducibility. The responsivity and photoconductive gain were estimated to be 3×10 A/W and 10 , respectively, which were much higher than other ZnO nanostructure-based devices. In addition, it was found that the on/off ratio of the present device can be considerably improved from 2.09 to 12.1, when the device was passivated by a layer of AlO film. These results suggest that the present simply structured graphene-ZnO UV photodiode may find potential application in future optoelectronic devices.
Sequential occurrence of eclampsia-associated posterior reversible encephalopathy syndrome and reversible splenial lesion syndrome (a case report): proposal of a novel pathogenesis for reversible splenial lesion syndrome
Background Posterior reversible encephalopathy syndrome (PRES) is a rare clinic-radiological entity characterized by headache, an altered mental status, visual disturbances, and seizures. Reversible splenial lesion syndrome (RESLES) is a new clinic-radiological syndrome characterized by the presence of reversible lesions with transiently restricted diffusion (cytotoxic edema) in the splenium of the corpus callosum (SCC) on magnetic resonance (MR) images. Here we report a rare case involving a 23-year-old pregnant woman with eclampsia who sequentially developed PRES and RESLES. Case presentation The patient, a 23-year-old pregnant woman, presented with sudden-onset headache, dizziness, and severe hypertension (blood pressure, 170/110 mmHg). Brain MR imaging (MRI) revealed T2 hyperintense lesions in the posterior circulation territories. Immediate cesarean section was performed, and the patient received intravenous infusion of mannitol (125 ml, q8h) for 8 days for the treatment of PRES. Ten days later, or 1 day after the discontinuation of mannitol, T2-weighted MRI showed that the hyperintense lesions (vasogenic edema) had disappeared. However, diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping revealed an isolated lesion in the splenium of the corpus callosum (SCC) that was accompanied by restricted diffusion (cytotoxic edema); these findings indicated reversible splenial lesion syndrome (RESLES). Five days after the discontinuation of mannitol, she had no abnormal symptoms and was discharged from our hospital. Brain MRI performed 29 days after the clinical onset of symptoms showed no abnormalities. Conclusion The sequential occurrence of the two reversible diseases in our patient prompted us to propose a novel pathogenesis for RESLES. Specifically, we believe that the vasogenic edema in PRES was reduced with mannitol treatment, which increased the hyperosmotic stress and opened the blood–brain barrier; meanwhile, upregulation of aquaporin-4 expression secondary to the increased osmotic pressure resulted in cytotoxic edema in the astrocytes in SCC (RESLES). Further research is necessary to confirm this possible pathogenesis.
Induction Profile of MANF/ARMET by Cerebral Ischemia and its Implication for Neuron Protection
Cerebral ischemia-induced accumulation of unfolded proteins in vulnerable neurons triggers endoplasmic reticulum (ER) stress. Arginine-rich, mutated in early stage tumors (ARMET) is an ER stress-inducible protein and upregulated in the early stage of cerebral ischemia. The purposes of this study were to investigate the characteristics and implications of ARMET expression induced by focal cerebral ischemia. Focal cerebral ischemia in rats was induced by right middle cerebral artery occlusion with a suture; ischemic lesions were assessed by magnetic resonance imaging and histology; neuronal apoptosis was determined by TUNEL staining; the expressions of proteins were measured by immunohistochemistry, immunofluorescent labeling, and Western blotting. ARMET was found to be extensively upregulated in ischemic regions in a time-dependent manner. The expression of ARMET was neuronal in all examined structures in response to the ischemic insult. We also found that ARMET expression is earlier and more sensitive to ischemic stimulation than C/EBP homologous protein (CHOP). ER stress agent tunicamycin induced ARMET and CHOP expressions in the primary cultured neurons. Treatment with recombinant human ARMET promoted neuron proliferation and prevented from neuron apoptosis induced by tunicamycin. These results suggest that cerebral ischemia-induced ARMET expression may be protective to the neurons.
Relationship between cerebellar structure and emotional memory in depression
Background A few studies have been conducted on the relationship between cerebellar volume and emotional memory or clinical severity in major depressive disorder (MDD). In this study, we aimed to compare the volume and density of the cerebellar gray matter (GM) in patients with MDD and in healthy controls (HCs) and explore the association between these cerebellar parameters and measurements of emotional memory and clinical severity. Method Voxel‐based morphometry (VBM) and Individual Brain Atlases using Statistical Parametric Mapping (IBASPM) were used to assess GM density and volume in the cerebellum, respectively, in patients with MDD and the HCs. Indicators of emotional memory performance were measured, including the hit rate (HR), rate of false alarm (FA), precision (Pr = HR − FA) and emotional memory enhancement [∆Pr = Pr(emotion) − Pr(neutral)] values. Beck Depression Inventory (BDI) scores were used to measure the severity of depression. Results In the patients with MDD, the GM density was decreased in three cerebellar cortical regions and increased in three cerebellar cortical regions (p < .005). The GM volumes in eight cerebellar cortical regions were significantly smaller in the patients with MDD than in the HC subjects (p < .05). In the patients with MDD, the GM volume was correlated with the ∆Pr (p < .05) in two cerebellar cortical regions. The BDI scores were significantly correlated with the relative GM densities (p < .05) in 5 cerebellar cortical regions, and the GM volumes in 13 cerebellar cortical regions were correlated with the BDI scores in patients with MDD. Conclusions Emotional memory and the severity of depressive symptoms are associated with structural changes in both the posterior and anterior GM regions in the cerebellum in patients with MDD. These findings could be useful for improving our understanding of the neurobiological mechanisms underlying emotional memory and explaining the abnormalities of the neural correlates that are associated with MDD. Emotional memory and the severity of depressive symptoms are associated with structural changes in both the posterior and anterior GM regions in the cerebellum in patients with MDD. These findings could be useful for improving our understanding of the neurobiological mechanisms underlying emotional memory and explaining the abnormalities of the neural correlates that are associated with MDD.
Processing Deficits of Motion of Contrast-Modulated Gratings in Anisometropic Amblyopia
Several studies have indicated substantial processing deficits for static second-order stimuli in amblyopia. However, less is known about the perception of second-order moving gratings. To investigate this issue, we measured the contrast sensitivity for second-order (contrast-modulated) moving gratings in seven anisometropic amblyopes and ten normal controls. The measurements were performed with non-equated carriers and a series of equated carriers. For comparison, the sensitivity for first-order motion and static second-order stimuli was also measured. Most of the amblyopic eyes (AEs) showed reduced sensitivity for second-order moving gratings relative to their non-amblyopic eyes (NAEs) and the dominant eyes (CEs) of normal control subjects, even when the detectability of the noise carriers was carefully controlled, suggesting substantial processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia. In contrast, the non-amblyopic eyes of the anisometropic amblyopes were relatively spared. As a group, NAEs showed statistically comparable performance to CEs. We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies. In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings. These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia.